Development of porous carbon material `woodceramics' - frictional properties

Woodceramics are the porous carbon materials obtained from wood or woody materials impregnated with phenol formaldehyde resin and sintered in a vacuum furnace. The purpose of this paper is to analyze fundamental friction properties of woodceramics in sliding with several materials. A reciprocating friction apparatus was used in the experiments. An alumina ball (R = 1.5 mm, 4.0 mm), a silicon nitride ball (R = 4.0 mm), a bearing steel ball (R = 4.0 mm) and a diamond pin (R = 0.075 mm) were used for the upper specimens, and several woodceramics made of medium density fibreboard (MDF) and beech wood, impregnated with phenol formaldehyde resin and sintered in a vacuum furnace, were used for the lower specimens. The experiments were carried out under an unlubricated condition in air, under a base-oil impregnated condition and in water, with several normal loads at different sliding velocities. The following principal results were obtained in this investigation. (1) The friction coefficient is around 0.15 under the unlubricated condition in air, under the base-oil impregnated condition and in water. (2) The friction coefficient slightly decreases and then keeps a constant value with increasing normal load. (3) The friction coefficient is not affected by sliding velocity. (4) Woodceramics have a good self-lubricity.